66 ISSN East Cent. Afr. J. surg

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1 66 Identification of the Commonest Snake Species Causing Envenoming and Fatality among Snake Bites of Venomous Admission in Dilchora Referral Hospital. D. Manyazewal. Consultant Orthopedic Surgeon Dilchora Referral Hospital, Dire Dawa, Eastern Ethiopia. Background: Snake bite is a common medical emergency in developing countries. The identification of snake species is important for optimal clinical management, because it allows clinicians to choose the appropriate treatment, anticipate complications, and there fore to improve prognosis. Moreover, helps in selection of specific antivenom and avoids antivenominduced adverse reactions. The Objective the study is to Identify the commonest Snake species causing envenoming & fatal bites among snake bites of venomous admission in Dilchora referral Hospital from Methods: The diagnosis was based on the history and account of injury, observation of fang marks, snake identification (when possible) and signs and symptoms of envenoming in patients admitted to orthopedic ward for Supportive therapy without antivenom. Recording of necessary data and analysis were done by the Author. The study was conducted from Results: During the study period a total of 110(60 Male 54.5% and 40 Female 45.5% ) envenomed patients were admitted in our orthopedic ward making male to female ratio 1.2:1(Table 1). Bites in Under 15 years account for 36(32.7%), in years for 69(62.7%), in years for 5(4.5%)(Table 1). Bite on the upper limb account for 40(36.4%), on the Lower limb for 66(60%) and on the head & trunk region 4(3.6%)(Table 2). Fatal bite account for 7( 6.4%)(Table 3,4 &5). Known Poisonous snakes caused 86(78.2%) of total envenoming (Table5 and Figure 2). Conclusion: Viper and Puff adder snakes were the commonest causes of fatal bites in our Hospital. Measures to be under taken are recommended. Introduction Snake bite is a common medical emergency in developing countries 1. Antivenom is the only Specific antidote (treatment) to snake venom and its timely administration reverses all systemic manifestation of envenoming 1-4. WHO estimates that approximately 2,500,000 venomous snake bites per year result in 125,000 deaths world wid,100,000 of which are in Asia and approximately 20,000 in Africa 3,4. In Africa, the annual incidence rate of snake bite in the Benu Valley of North Eastern Nigeria is 497/100,000 population with a case fatality ratio 12.2% 2. Study done at a rural South African hospital showed that the case fatality rate for snake bite to be 2.9% 6. It is generally agreed that the case fatality rate of snake bite in developing countries varies from 2% to 10% The high case fatality ratio of snake bite in tropical developing countries is the result of a combination factors including the scarcity of antivenom, poor health service and problems with transportation from rural areas to health centers 2,5. An Intervention including development of treatment protocol, Staff training, monitoring of compliance and patient education decreased snake bite mortality from 11%(8/72) to 1.3%(3/238) in rural Ghana 11. The identification of snake species is important for optimal clinical management, because it allows clinicians to choose the appropriate treatment, anticipate complications, and therefore to improve prognosis. Moreover, helps in selection of specific antivenom and avoids antivenominduced adverse reactions 6,14,15.

2 Material and Methods: 67 The diagnosis of snake bite was based on the history and account of injury, observation of fang marks, snake identification (when possible) and signs and symptoms of envenoming in all patients admitted to orthopedic ward for Supportive therapy without antivenom (antivenom is not available in our hospital). Identification of known Venomous snakes were performed by the author using bed side 20-minutes whole blood clotting test(20wbct) to snake bite Victims with clinical sign of swelling and by comparing dead snakes presented in our hospital by patient s family with Online Pictures of venomous Snakes of Africa [ Recording of necessary data and analysis were done by the author. The study was conducted from Results During the study period a total of 110 envenomed patients were admitted in our orthopedic ward. The males were 60 (54.5%0 and 50 (45.5%) were females. The male to female ratio was 1.2:1. The under 15-years accounted for 36 (32.7%) of the cases of snake bites. The majority (62.7%) of the patients were in the years age group (Table 1). Table1. Number of Envenomed Cases of Snake Bites by Gender and Age in Years from Age in Years Gender Total Male Female 0-4 6(5.5%) 5(4.5%) 11(10%) (9.1%) 15(13.6%) 25(22.7%) (12.7%) 8(7.3%) 22(20%) (18.2%) 17(15.5%) 37(33.6%) (5.5%) 4(3.6%) 10(9.1%) (3.6%) 1(0.9%) 5(4.5%) Total 60(54.5%) 50(45.5%) 110(100%) Table 2. Number of Envenomed Cases of Snake Bite by Main Clinical Syndrome and Location of Bite from Clinical Syndrome Location of the bite Total Upper limb Lower Head & Limb Trunk Syndrome 1:Massive 30(27.3%) - 71(64.5%) Swelling with Incoagulable 41(37.2%) blood Syndrome 2: Massive 7(6.4%) 2(1.8%) 28(25.5%) Swelling with Coagulable 19(17.3%) blood Syndrome 3: Mild swelling 3(2.7%) 6(5.5%) 2(1.8%) 11(10%) only with Coagulable blood Syndrome 4: Neurotoxicity or paralysis Total 40((36.4%) 66(60%) 4(3.6%) 110(100%)

3 68 Table 3. Number of Envenomed Cases of Snake Bite by Age in Years and Outcome of Bites Age in Years Out come of the bite Total Fatal Non fatal 0-4 2(1.8%) 9(8.2%) 11 (10%) (22.7%) 25 (22.7%) (20%) 22 (20%) (1.8) 35(31.8%) 37 (33.6%) (2.7%) 7(6.4%) 10 (9.1%) (4.5%) 5 (4.5%) Total 7(6.4%) 103(93.6%) 110(100%) Table 4. Number of Envenomed Cases by Clinical Syndromes and Outcome of the Bites Clinical Syndrome Outcome 0f the bite Total Fatal Non-Fatal Syndrome 1:Massive Swelling with 5(4.6%) 65(59.1%) 70(63.7%) incoagulable blood Syndrome 2:Massive Swelling with coagulable blood 2(1.8%) 24(21.8%) 26(23.6%) Syndrome 3:Mild swelling only with - 14(12.7%) 14(12.7%) coagulable blood Syndrome 4: Neurotoxicity/Paralysis Total 7(6.4%) 103(93.6%) 110(100%) Table 5. Number of envenomed cases by types of snake species identified and Out come of the bite from Types of Snake Species Identified Out come of the bite Total Fatal Non fatal 1. Africa s Known most dangerous snake [ 1.1 Saw-Scaled or carpet Viper 5(4.5%) 58(52.7%) 63(57.3%) 1.2 Puff Adder 2(1.8%) 21(19.1%) 23(20.9%) Other local Snake Species presented to our Hospital - 9(8.2%) 9(8.2%) 3. No Snake identified - 15(13.6%) 15(13.6%) Total 7(6.4%) 103(93.6%) 110(100%)

4 69 Figure 1. shows the results of 20-minutes whole blood clotting test for victims of snake bite With clinical swellings. Coagulable blood (Rt. Hand) and incoagulable blood (Lt.Hand) Viper Puff Adder Figure 2. Shows the two Dead snake species caused envenoming & fatal bites as presented for identification by families in Dilchora referral hospital from Bite on the upper limb accounted for 40 (36.4%), on the Lower limb for 66(60%) and on the head & trunk region for 4(3.6%) of the cases. Massive local swelling with incoagulable blood occurred in 71(64.5%) of the clinical syndrome, Massive local swelling with coagulable blood were seen in 28(25.5%) of the clinical syndrome, Mild local swelling with coagulable blood in 11(10%) of the clinical syndrome and there was no cases presenting with clinical Syndrome of neurotoxicity/paralysis (Table 2 and Figure1). There were 7 deaths, giving a fatality rate of 6.4% (Table 3,4 and 5). Known Poisonous snakes caused 86(78.2%) of total envenoming (Table 5 and Figure 2). Discussion The study has shown that majority (62.7%) of the envenoming occurred in young adults agd years followed by Children under 15 years (32.7%). The finding is in agreement with other reports 6,12,13,14. Most (64%) bite occurred to the lower limb. This is also consistent with many Studies 6,12,14. It is also evident that massive local swelling with incoagulable blood is the commonest (64.5%) clinical syndrome followed by massive local swelling with coagulable blood(25.5%). Such clinical syndromes were documented in bites with saw scaled viper and

5 70 puff adder snake species respectively 13. During the study period there was no single patient admitted with clinical syndrome of neurotoxicity/paralysis indicating that snake bites due to Cobra and mambas species were rare to find in our hospital 13. Saw-scaled viper and puff adder snakes were the leading species resulting venomous admission and fatal bites in our hospital. Case fatality between syndrome1 and syndrome 2 presentations and between Viper and Puff adder snakes bite did not show statistically significant difference (P<0.05). The identification of snake species is important for optimal clinical management, because it allows clinicians to choose the appropriate treatment, anticipate complications, and therefore to improve prognosis. Moreover, helps in selection of specific antivenom and avoids antivenom-induced adverse reactions 6,14,15. Hence, It is crucial for physicians and other Health workers to be familiar with the most common venomous snakes in Ethiopia and the management of their bites in humans. The proportion of fatal bites 6.4% documented in this study is higher than the recent finding 1.3% in rural Ghana 11 and 2.9% in South Africa 6 However it is significantly Lower than the finding 12.2% in Nigeria 2. Higher proportion of fatal bites documented in our study is due to lack of comprehensive Interventions including use of antivenom, development of treatment protocol, Staff training, monitoring of compliance and patient education 11. Conclusion Viper and Puff adder snakes were found to be the commonest causes of envenoming and fatal bites in our Hospital. Hence procurement of antivenom in our Hospital must ensure the consideration of these two venomous species. Recommendation 1. Further nation wide study to document the most common venomous snakes species, incidence, morbidity, and mortality of snake bites in Ethiopia. 2. Interventions including use of Antivenom, Development of management protocol, staff training etc. should be implemented to decrease morbidity and mortality of snake bites in Ethiopia. 3. Education of rural communities on snake bite, avoidance of useless or dangerous firstaid measures, and the importance of rapid transport of victims to treatment centers should be widely implemented. Acknowledgement I would like to pass my heart felt thanks to Ato Anteneh Mekonen, Chief librarian Dilchora Hospital, Who helped me in downloading the Online pictures of Venomous Snakes of Africa and the patient s family who brought the dead snakes to Dilchora Hospital. References 1. Stock RP, Massougbodji A, Alagon A, Chippaux JP.Bringing antivenom to sub-saharan Africa. Nat Biotechnol.2007; [pub Med] 2. Guti errez JM,Theakston RD, Warrel DA.Confronting the neglected problem of snake bite envenoming: the need for Global partner ship.plos Med.2006;3(6):e Pinho FM, Zanetta DM,Burdmann EA. Acute renal failure after Crotalus durissus snake bite: a prospective survey on 100 patients.kidney Int.2005;67: Sitprija V.snake bite nephropathy.2006; 11: Cheng AC,Winkel K.call for Global Snake bite control and procurement funding.lancet.2001; 357:1132.

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